Air Quality - Want to know if consecutive value is above certain threshold for 24 hours

[kish]

Dear all,

I need some help with figuring out my Air Quality Data. I have a device measuring PM2,5 every 5 minutes. To know whether the air quality meets criteria set by the WHO, I need to know if my measurements keep above 15 ug/m3 for 24 hours continuously. For this I need to know whether my column displays a value 288x >15 consecutively. However, I have no idea how to come up with a calculation that does do this. Any help?

 

[kish]

Dear all,

I need some help with figuring out my Air Quality Data. I have a device measuring PM2,5 every 5 minutes. To know whether the air quality meets criteria set by the WHO, I need to know if my measurements keep above 15 ug/m3 for 24 hours continuously. For this I need to know whether my column displays a value 288x >15 consecutively. However, I have no idea how to come up with a calculation that does do this. Any help?

I see that I made a critical thinking error:

What I want is to seek whether the 24-hour average is above 15 ug/m3. If so, I want to count the amount of days with an average above 15 ug/m3. Hope this helps

 

[Beneindias]

I don't know if I understood your problem right.

To calculate average, you can use AVERAGE function (lets assume you have your data for 1 day in column A)

=AVERAGE(A1:A288)

Now, if you have the average in row 289.

You can count the days that average higher than 15, with the folowing function

=COUNTIF(A289:X289;">15")

(assuming first column A, and last column X)

Is this what you need? If not, you will need to explain your problem better

Hope it helps

 

[Fluff]

It would help if you could post some sample data, along with expected results.

MrExcel has a tool called “XL2BB” that lets you post samples of your data that will allow us to copy/paste it to our Excel spreadsheets, so we can work with the same copy of data that you are. Instructions on using this tool can be found here: XL2BB Add-in

Note that there is also a "Test Here” forum on this board. This is a place where you can test using this tool (or any other posting techniques that you want to test) before trying to use those tools in your actual posts.